U.S. Pat. No. 4,456,072 discloses a fixed structure for location over a submerged drill site in waters which normally freeze in winter. The structure comprises generally concentric vertically oriented cylindrical inner and outer walls which define an annular space therebetween. This space is filled with ice, and when completed, the walls extend down to the seabed and the intervening space is filled with ice. The area inside the inner wall thus defines an enclosed volume of water which can be prevented from freezing relatively easily, such as by spreading a layer of insulating material on the surface of the water, and within this area operations such as drilling for offshore oil can proceed throughout the winter.
A disadvantage with this structure is that although it provides an artificial island, its use is limited to waters which normally freeze in winter. Thus its use is confined to a limited geographical area and to a seasonal period only. While this is adequate for the purposes for which it is intended (maintaining a drilling site in winter), and while the geographical and seasonal limitations of this technology are not drawbacks in the application in question (since the structure is only required during that season and in that region), the structures disclosed in U.S. Pat. No. 4,456,072 are of limited application.
A further limitation with the structures of U.S. Pat. No. 4,456,072 is that they require fixing to the seabed and cannot be used in locations where the water is relatively deep.
Suggestions have been made for transporting ice to more temperate climates, such as towing large ice floes to drought affected areas, on the assumption that melting losses during the journey will not be too great. Such suggestions have not been put into practice, and they highlight the perceived reasons for the limited use of ice outside arctic or antarctic regions, namely that refrigeration costs are thought to be prohibitive in any large-scale or long-term use of ice.
While there have undoubtedly been other proposals for and uses of ice in structural applications, the general problem with these structures is that their use is subject to geographical and/or seasonal limitations.
It is an object of this invention to provide an ice composite body in which the above cited disadvantages are reduced or eliminated, the potential structural applications of ice composite bodies realised and particularly the ability realised to make dimensionally stable ice composite structures of any desired shape and design.